A fan of an aircraft engine takes the air into: an annular core passage (a main passage) formed inside a barrel-shaped engine main body (an engine internal barrel); and a bypass passage formed between the outer peripheral surface of the engine main body and the inner peripheral surface of a barrel-shaped fan case placed outside the engine main body. A general configuration of the fan is as follows.
A fan disk is rotatably provided to the front portion of the engine main body. Multiple fan rotor blades are provided to the outer peripheral surface of the fan disk at equal intervals in the circumferential direction. In addition, multiple guide vanes are provided downstream of the fan rotor blades between the engine main body and the fan case at equal intervals in the circumferential direction. The multiple guide vanes straighten the flow of the air taken into the bypass passage.
In this respect, the multiple guide vanes may have a function as a structural body configured to integrally connect the fan case to a fan frame which is part of the engine main body in addition to the function of straightening the airflow, or may only have the function of straightening the airflow. In the former case, a metal such as an aluminum alloy is typically used as the constituent material of the guide vanes. In the latter case, a metal such as an aluminum alloy, or a composite material made of a thermosetting resin such as an epoxy resin and reinforcement fibers such as carbon fibers is typically used as the constituent material of the guide vanes. Moreover, the latter case uses multiple struts which are placed downstream of the guide vanes at intervals in the circumferential direction and whose constituent material is a metal such as an aluminum alloy, and makes the struts partially bear the function as the structural body.
It should be noted that the art disclosed by Patent Documents 1 to 3 is the background art related to the present invention.